Switch construction



SWITCH CONSTRUCTION Filed Aug. 26, 1955 6 Sheets-Sheet l INVENTORJ March 7,1939. w. o. SCHULTZ E AL SWITCH CONSTRUCTION Filed Aug. 26, 1955 6 Sheets-Sheet 2 ATT '- March 7, 1939.

Filed Aug. 26, 1935 6 Sheets-Sheet Z A m Q) y I I E 1 l H i v I I! I: 1

n Q Hill" w 1 i '3 V I I I} Q T111? 3% g G j 7' Z g 1 1 1 {i l I INVENTORJ w 0% a JMa/ i N BY WM 9 ffa/zmwyzfl My W91 March 7, 1939. w. o SCHULTZ ET AL 2,149,365

I SWITCH CONSTRUCTION Filed Aug. 26, 1935 6 Sheets-Sheet 4 7 March 7, 1939} w. o. SCHULTZ ET AL SWITCH CONSTRUCTION 6 Sheets-Sheet 5 Filed Aug. 26, 1935 A RNEY.

March 1939- w. o. SCHULTZ a r AL 2,149,365

SWITCH coNsTRucTIoN ATI' Patented Mar. 7, 1939 PATENT OFFICE 2,149,365 swrrcn CONSTRUCTION William 0. Schultz, South Milwaukee, and Alwin G. Steinmayer,

Milwaukee, Wis., assignors to Hue Material'Compauy, South Milwaukee,

Wis., a corporation of Delaware Application August 26, 1935, Serial No. 37,830

7 Claims.

This invention relates to a switch construction and is particularly directed to a high voltage switch, such as a disconnecting switch, for instance, although the invention is not limited to this type of switch.

Objects oi. this invention are to provide a construction in which a multiple switch is provided, that is, in which a plurality of simultaneously actuated switch arms are provided, in which the switch arms may be very long, for example fifteen ieet if desired, to provide adequate clearance between the stationary and movable contacts when the switch is opened so as to provide a serviceable and reliable high voltageswitch.

When it is considered that these high voltage switches are of considerable size, it is at once apparent that inaccuracies in drilling the holes, machining, or other work may cause over-travel oi the parts. However, this invention provides a construction which overcomes the defect of overtravel and overcomes the necessity of requiring absolute accuracy and precision in the machine work, but instead provides means for preventing over-travel and yet insures accurate cooperation for alignment of the coacting contacts.

Further objects are to provide a switch construction in which the actuating rod and main switch arm form in eifect a truss construction and secure maximum strength with minimum weight, and in which the construction allows for lateral bracing as well as vertical bracing by having a frame work construction for the main switch arm, thus maintaining the lightness of construction and also providing strength against lateral deflection or displacement.

When it is considered that these switches have very long switch arms, it is apparent that any ice seal at the contacts or any sticking or corrosion or roughness of these parts might cause a very great strain to be imposed on the mechanism in order to break this seal.

This invention, however, provides a construction in which a novel form of mechanism is used to first movefthe movable switch blade or auxiliary switch blade from the stationary contacts, preferably from between coacting pairs of stationary contacts, without imposing any great strain upon the mechanism, and in which the mechanism thereafter moves the main switch arm from adjacent the stationary contacts and provides the wide separation necessary for high voltage service.

In greater detail, further objects of this invention are to provide a switch construction in which the auxiliary blade is pivoted and opens downwardly away from the stationary contacts, and in which a; protecting hood, such as a sleet hood, is provided for the stationary contacts, such hood having a permanently unbroken top so that ice and sleet cannot collect or form at the stationary contacts, and in which means are provided for bringing the movable or auxiliary switch blade upwardly into engagement preferably between the stationary contacts, to thus avoid the news; sity of splitting or opening the sleet hood at its top, the invention also contemplating the provision of a sleet hood or protecting hood over the latch means or movable blade of the main switch arm if so desired.

Further objects are to provide a novel form of stationary contact and cooperating movable auxiliary switch blade which is so formed that the movable blade, as stated, opens downwardly and the stationary contacts are held in a floating manner andare freely shiftable so as to maintain an extensive surface contact with the movable switch blade, and in which'individual leaders or flexible conductors are provided for each element of the stationary contact and for the movable switch blade to thus avoid having current pass through the joints or supporting means for such members.

Further objects are to provide a construction in which latching means is provided for locking the movable switch blade against closing motion after it has once been opened until the main switch arm has been rocked downwardly to its fully closed position, such latching means preventing any possibility of jamming of the contacts.

Further objects are to provide a construction in which are horns are furnished and act not only as are horns but also as guides to assist in positioning the movable switch blade or auxiliary switch blade, and in which these are horns maintain contact with portion of the main switch arm, for instance with the auxiliary, somewhat flexible arms carried on the main switch arm, after the movable or auxiliary switch blade has cleared the stationary contacts, thus preventing any chance of arcing at the movable and stationary once apparent that stresses tending to break must be placed on such insulator stacks.

This invention, therefore, has for its still further objects the provision of a switch construction in which no twisting motion is imparted to the stack of insulators that carry the stationary contacts, and in which no tendency to draw the insulators towards each other is produced in the operation of the mechanism, and in which no lateral deflection of the insulator stacks occurs, the insulator stacks, therefore, being protected against breaking stresses.

Further objects are to provide a construction in which although one of the two insulator stacks at the pivoted end of the switch blade operates in the capacity of actuating mechanism, nevertheless such stack is braced'from the adjacent stationary insulator stack so that the pull of the actuating mechanism is not transmittedto these stacks but is borne by the bracing member between the stacks, thus additionally guarding against damage to the parts.

Further objects are to provide a construction in which a very simple arrangement is provided for simultaneously operating all of the switch arms, and in which the construction is such that any number of switch arms may be provided by a simple extension of the main supporting frame and the positioning ofthe corresponding additional number of switch arms on such supporting frame.

Embodiments of the invention are shown in the accompanying drawings, in which:

Figure Iis a side view of the switch construction, such view showing the switch in closed position in full lines and in raised or open position in dotted lines.

Figure 2 is a fragmentary plan view of the structure shown in Figure 1.

Figure 3 is an enlarged view, with parts broken away and in section, showing the stationary contacts and cooperating auxiliary or movable contact, such view showing the auxiliary switch blade in closed position in full lines and showing the auxiliary switch blade in open position in dotted lines.

Figure 4 is a fragmentary view from the under side of Figure 3. .1

Figure 5 is a fragmentary view showing the pivoted end of the main switch arm and the adjacent portions of the mechanism.

Figure 6 is a fragmentary sectional view on the line 6--6 of Figure 1, with parts broken away.

Figure 7 is a view of the bottom or supporting frame and a portion of the operating mechanism.

for simultaneously operating a plurality of switch blades, such view having the insulator stacks and the upper mechanism sectioned ofl.

Figure 8 is a view of a further form of the invention, such view showing the auxiliary contact or switch armand stationary contacts.

Figure 9 is a view of the pivoted end of the ,main switch arm and a portion of the associated A-plurality of switch units are simultaneojisly operated and the operating mechanism for the switch units may take the form of a crank or similar member indicated by the reference character 2 in Figure 7 and coupled to the individual rock levers 3' for the several switch units, as indicated in Figure '7, by means of a series of conseen from Figure 1, the insulator stack Ill is pro- I vided for the stationary contacts and a widely spaced insulator stack I l is provided for the pivoted end of the main switch arm l2, a rotary insulator. stack l3 being carried by each of the levers 3 so that rotation -.of the crank 2 or operating mechanism rotates the insulator stack l3, see Figure 1. v

The insulator stack [3 carries a shaft M which projects through a bearing formed in the bracing member IS, the bracing member extending across and forming a bearing or supporting member for the pivot pin l6 of the main switch arm I 2, as clearly shown in Figures 1, 2 and 5.

If desired, a spring or counter-weight may be used to counterbalance the weight of the main switch arm. For example, as shown most clearly in Figure 5, a spring H is employed and has one end secured to the member l5 and the other end secured to a bracket or transverse member l8 carried by the main switch arm l2.

In reality, the main switch arm I2 is composed of a pair of spaced bars which converge towards their outer or free ends, as shown clearly in Figure 2, and which are braced at intervals by transverse braces, as may be seen from Figure 2.

It is preferable to form the two elements of the. main switch arm of channel construction, as most clearly shown in Figure 1, to thereby secure the great strength with relatively light weight. An auxiliary or movable switch blade I9 is pivoted between the outer ends of the main switch arm and is carried by the pivot pin 20, see Figure 3.

This auxiliary switch blade is provided with an outwardly projecting arm which is pivoted as indicated at 2| ton. head22 carried by the operating rod 23. The rod 23 has been shown solid in the drawings, but obviously for lightness it could be made in the form of a. pipe. The auxiliary switch blade is connected by means of a flexible leader or conductor 24 with the terminal member 25, as shown at the left hand end of Figure 2. Preferably the flexible leader 24 is formed either bifurcated or formed of two strands, as indicated in Figure 2, so that the elements thereof may be spaced and positioned on opposite sides of the main switch arm I2. Thus a direct electrical connection is provided between the auxiliary switch blade i 9 and the terminal member 25.

With regard to the terminal member 25, it is apparent from the, description thus far given that when the operating rod 23, see Figure 3, is drawn to the left, the first effect is to rock the auxiliary switch arm i9 downwardly into the dotted line position. Thereafter the shouldered portion 26 of the head 22 of the operating rod 23 is in position to be engaged by the shouldered portion 21 of'the looking or latch lever 23,

such latch lever being pivoted as indicated at 23 and carried by the mainswitch arm 12 and loosely receiving a bolt or pin 30 about which a coil spring 3| is loosely wrapped and bears downwardly upon the latch lever 23. The release of the latch lever for locking engagement with the operating rod ,23

through the medium of the shouldered portions 26 and 21 will hereinafter be described.

Ifdesired, a cam sleeve llll may be adjustably locked to the pull rod 23 and may engage the lip I02 of the lever 23' to insure the downward motion of the lever 23 after the face '26 has moved past face 21. If this construction is employed, it is obvious that a little play will have to be left be- ,tween the faces26 and 21 so that the sleeve "ll will clear the extension I02 prior to engagement of the faces 26 and 21.

.If desired, a sleet hood or protecting hood 32 may be positioned'overthe active interlocking portions of the mechanism, as shown, or if desired, this hood may'project considerably farther to the rightfrom the position shown in-Figure 3 to afford a hood for more of the mechanism, as will be apparent from the detailed description -of further forms of the invention.

Returning to Figures 1, 2 and5, it will be noted 7 that the pivoted end of the main switch arm l2 has relatively widely spaced portions and if desired adjustable stops 33 may be provided for en gaging the main switch arm and limiting itsextreme upper position.

The inner end of the operating rod 23 is pivoted v between the arms of a lever 34, see Figures 1 and 5, which is itself pivotally carried by the pivot pin 16 of the main switch arml2. This lever also pivotally carries the fitting 35, see Figures 2 and 5,, which is pivoted upon the pin 36 connecting the operating rod or pull rod 23 of the main switch blade with the lever 34.

The fitting 35 is'pivoted to the connecting rod 31, seeFigures 2 and 5, the pivotal axis of this connection being at right angles to that of the pin 36, to thus provide a universal joint. The inner end of the connecting rod 31 is connected by means of a universal joint 33 with the crank 39,

, tation of the crank arm 39 and from reference to Figure 3, itwill be seen that at this point approximately maximum leverage is afiorded at the point where the connecting rod or pull rod 23 joins the movable switch blade I3. The result of this construction is that maximumeifort is exerted upon the movable switch blade l3, see Figure 3, to thus easily break any ice seal or corrosion or sticking between the movable and stationary contacts.

' Thereafter the movable switch blade or auxiliary switch blade l3 rocks to the dotted line position and the pin 21 contacts with the arms 12 of the main switch arm, arresting further rocking motion of the auxiliary switch blade, such position of the parts being, shown in dotted lines in Figure 3. Continued rotation of the crank 39 in Figure 1, and thus spaces the" pull rod 23 further upwardly from the main switch arm 12, providing an increased truss effect. Upon continued rotation of the crank 33, the main switch arm I2 is rocked upwardly to the dotted line position, the auxiliary switch blade it having previously withdrawn itself from engagement with the stationary contacts hereinafter described.

As the main switch arm rocks upwardly, the latch lever 234s lifted from engagement with the projecting portion 40 of the sleet hood 4|, see Figure 3, such sleet hood being carried by the insulator stack ill and thus the spring pressed latch lever 23 moves downwardly and locks against the shoulder 26, thus locking the auxiliary switch blade in open position.

"The sleet hood 4| for the stationary contacts may continue outwardly and form the terminal portion which is carried by the insulator stack 10, a terminal member 42 being provided, as shown in Figures 1 and 2.

The stationary contacts are positioned within the sleet hood 41 and are formed of two members or blades 43, see Figures 1, 3, 4 and 6. The blades or elements 43 of the stationary contact are divergent downwardly and outwardly to facilitate the entry of the movable or auxiliary switch blade l9 therebetween. Further than this, the front wall of-the sleet hood or protecting hood 4! is provided with a slotted portion, the slot being formed. downwardly divergent or tapered as indicated at 44 in Figures 4 and 6, to thereby further aid in the guiding of the movable switch blade l9 into position between the elements 43 of the stationary contacts. These elements are each provided with a flexible leader or connector 45 which extends rearwardly directly to the terminal member 42, see Figures 1, 3, 4 and 6.

It is to be noted, particularly from Figure 3, that the sleet hood has downwardly hanging front, rear and side portions which constitute drip portions which are positioned beyond the stationary contact and thus cause any water falling upon the hood to drip downwardly and preclude the water from following along the inner surface of the hood to the stationary contact.

At this point attention is called to the fact that anchoring means, such as the U-bolts 46, may be provided for the conductors leading to the terminal members 42 and 25, see Figures 1 and 2, to thus relieve the terminal members 25 and 42 of mechanical strain due to the pull of the conductors not shown. The sleet hood is provided interiorly and on opposite sides with socket members 41. Pins 43 formed rigidly with bases 49 are slidably and loosely received within the sockets 41 and the bases 49 of these pins are rigidly secured to the contact members 43, a spring 50 being provided for each contact member and positioned between the bases 49 and the socket members 41, as shown most clearly in Figure 6, thus constantly urging the contact members 43 towards each other, though allowing free floating of these members. The contact members 41 are prevented from rocking out of place by the flexible leaders 45. These leaders are relatively wide and though theyallow free floating of the contacts, there is sumcient strength in the leaders to prevent undue rocking oi the contacts.

Arc horns 5| project upwardly from adjacent the stationary contact with .the switch and are carried by the sleet hood 4|- This hood is provided with projecting portions which receive the lower ends of the arc horns and such arc horns are locked in; place many suitable manner, as by means of screws 52, so that theymay be renewed when desired. v

These-arc horns converge towards their upper ends, as shown particularly in Figure 6.

A pair of somewhat springy guiding arms 53 are positionedon opposite sides of and carried by the main switch arm l2. These arms 53, see Figure 6, are guided on opposite sides of the arc horns 5| and are the last portions of the switch to remain electrically connected to the stationary contacts when the switch is being opened, good contact being maintained by the resilient presing of the arms 53 against the sidesv of the arc horns 5|. Additionally, they serveto assist in guiding theswitch into position when it is being closed as they ride downwardly on opposite sides of the arc horns in the final closing motion of the switch. It will be seen that there are two guiding means provided which become activewhen the switch is being closed. The first guiding means roughly guides the main switch arm into place and comprises the horns 5| and the members or horns 53. This is the rough guiding means for positioning the main switch arm. Thereafter the slotted front of the hood, the slot being indicated at 44 see Figure 6, forms a more accurate guiding means for guiding the auxiliary switch arm or switch blade into engagement with the stationary contacts.

The operation of the switch is as follows: When it is desired to open the switch, the operating crank or member 2, see Figure '7, is rotated and thus rotates the members 3. Referring to Figure 1, it will be seen that when the member 3 is rotated, the crank 39 at the upper end of the re:- tary insulator stack l3 draws the link 31 and rod 23 to the left, as viewed in Figure 1. This causes the auxiliary switch blade Hi to move downwardly from between the stationary contacts 43, as shown most clearly in Figure 3.

The'movable switch arm rocks to the dotted line position in such Figure 3, and at this time the pin 2| contacts with the main switch arm l2 and stops further motion of the auxiliary switch blade. Continued pull on the rod 23 lifts the main switch arm upwardly to the dotted line position and after the latch lever 28, see Figure 3, is out of engagement with the rib 40 of the hood 4|, the shouldered portions 26 and 27. are in engagement: and thus the movable switch blade is locked against closing motion.

When the switch is closed by reverse rotation of the crank 39, see Figure 1, the main switch arm l2 moves downwardly and no relative motion can occur between the auxiliary switch blade l9 and the main switch arm, as these members are temporarily locked together, as described above.

- However, when the main switch arm has completed its closing motion, the latch lever 28, see

Figure 3, is raised and releases the auxiliary switch arm. This auxiliary switch arm is now rocked upwardly due to the final thrust of the rod 23 and passes between and separates the stationary contacts 43, see Figures 3 and 6. It is preferable to slightly bevel the upper edge of the movable switch blade IS. The stationary contacts 43 are floating and adjust themselves so that a perfect surface contact is made with the movable or auxiliary switch blade. This closing of the switch occurs without the necessity of having an opening in the upper face or top of the sleet hood 4| and consequently the stationary contacts are at all times fully protected from the weather.

Inthe form of the invention shown in Figures 8, 9 and 10 the rotary insulator stack is indicated at 54 and the stationary insulator stack for thepivotedend of the mainswitch arm 55 is indiportion 60, the face 60 continuing upwardly to the hooklike portion or stop member 6|.

The switch arm carries a lever 62 which is pivoted to the switch arm as indicated at 63 and the lever 62 is pivoted at its upper end to the pull rod or operating rod 64, and through the medium of the universal connection indicated generally at 65 is connected to the link 66. The lower end of the lever 52 carries a pin 61 which rides on the cam faces 59 and 60 for a purpose hereinafter to appear. The link 56 is connected by a universal joint construction 68' with the crank 69 carried by the rotary insulator stack 54. A bracing member 10 extends from the support 51 across the top of the insulator stack 54 and a centering shouldered bolt or screw 1| passes through the member 10 and into the upper face eg the crank, ,as is apparent from Figures 9 and The member 10 continues outwardly to form the terminal conductor receiving portion 12, see

Figure-10. A flexible connector 13 extends from the member 10, as shown in Figures 9 and 10. The flexible connector 13 is anchored as indicated at I4 and attached to a forwardly extending solid connector 15 carried by the main switch arm 55. This counector15 is anchored as indicated at 16 to a looped flexible connector 11 extending to the movable or auxiliary switch blade 18, see Figure 8. This movable switch blade is pivotcd at 19 and carried by the main switch arm 55. It is provided with a downwardly extending portion which is pivoted as indicated at to the operating or pull rod 64. The blade cooperates with stationary contacts 8| similar to those previously described, which are carried within an open bottom hood 82 similar to the hood previously described. This hood is provided with a closed top and is substantially the same as the hood previously described. The stationary contacts 8| are connected by means of flexible conductors 33 with the terminal member 84.

In this form of the invention a stop arm 65 is carried by the outer portion of the main switch arm 55 and when the switch is in closed position, it rests upon the top of the hood 82. Preferably the stop arm 85 is a looped, heavy rod like member arched downwardly, as shown in Figure 8. It limits the downward travel of the main'switch arm and takes care of any inaccuracies in machining or other work, so as to always stop the downward travel of the main switch arm at the exact point desired.

In the first described form of the invention, the arms 53 engage the stops 53' which project laterally from the hood 4| and thus arrest downward motion of the main switch arm at the correct point, irrespective of inaccuracies in machining.

The operation of the movable switch arm 18 is substantially the same as that previously described. -It is rocked downwardly during the initial opening motion of the switch before the switch arm begins'to move due to the pull of the rod 64. The rocking motion of the auxiliary switch blade 18 continues until the pin 80 strikes the under side of the arm 55, which arrest further motion of these parts. When this occurs,

the pin," has passed from beneath the face I. of the cam, see Figure 9, and allows the switch arm 98 to be raised. However, imtil the pin has passed from beneath the face "of the earn, up-

,wardmotion of the main switch arm is prevented. However, the pin now rides on the face 8| and opening motion 'of the main switch arm continues until the arm is approximately vertical.

As will be apparent from Figure 10, two of the cam members are provided, one located on each side of the apparatus, and the pin 61 continues completely across. Also the lever 82 is in reality formed in duplicate on opposite sides. The pin 91 engages the stops ii and limits the upward travel of the main switch In the closing motion of the switch relative motion between the movable switch blade 18 and the main switch arm 58 cannot occur, until the pin 81 has ridden down past the portion 08 and 'ontothe portion 59 of thecams. At this time the lever 62 can rock with relation to the main switch arm and consequently the auxiliary switch blade can now be operated. However, when the pin 61 passes from the surface 98 to the surface 59 of the cam, the stop 85 has just engaged the sleet-hood 82 and arrested further downward motion of the main switch arm. The lever 82 continues rocking and the rod 88 travels to the right with reference to the main switch arm 55, as viewedin Figures8 and 9. This causes the auxiliary switch blade 18 to rock upwardly into engagement with the stationary contact members 8| and to thus complete the closingmotion of the switch.

In the form of the invention shown in Figure 11, the stationary contact members are indicated at 88 and are carried within a hood 8! similar to that previously described. The movable or auxiliary switch blade 88 is pivoted as indicated at 89 to the main switch arm 98 and is pivoted as indicated at 9| to the operating rod or-push rod 92. It rocks relative to the main switch arm in identically the same manner as that previously described in connection with the first forms of the invention. It is connected to the main switch arm, as shown in Figure 11, by means of a flexible conductor 93 or it may be connected by means of flexible conductors to other conductors extending to the terminal member adjacent the pivot .of the main switch arm in the manner hereinbefore described.

However, the auxiliary switch blade 88 rigidly carries a cam member orsegment member 94 which has a shouldered portion 95 adapted to engage the shoulder 96 of the latch lever 91. This latch lever is provided with an opening 98 into which the segment member 94 passes when the latch lever locks the segment member, and

consequently the auxiliary switch blade 88, against motion.

This latch lever 91 is pivotally carried within a hood 99 rigidly mounted upon the switch arm'99 and is spring pressed downwardly preferably by means of the leaf spring I" as shown.

In this form of the invention the operating mechanism may be similar 'to that described in connection with Figure 1. when the operating rod 92 is drawn to the left, as viewed in Figure 11, the auxiliary switch blade is rocked downwardly to open position and the shoulders 95 and 98 come into approximate alignment. The pin 9| engages the under side of the main switch arm9ll and stops further rocking motion of the auxiliary switch blade 88. Continued'motion of like that previously described.

armand consequentlythelatchleverllislifted from engagement with the hood l1 and drops downwardly into locking position, thus locking the auxiliary-switch blade 88. However. when the switch isclosed. the latch lever 91 first en- 5 gages the hood 8l and is lifted so as to free the auxiliary switch blade 88. This blade can now be rocked upwardly into closed podtion into the open bottom hood I! in a manner identically Itwill beseenthatanovelformofswitchhas been provided which is eminently suitable for high voltage service as any desired distance of separation can be obtained. It is also obvious that this invention provides 1 a switch construction which does not depend for its perfect operation upon the precise accuracy of the machining, but which is so made that the main switch arm is arrested at the proper points in its travel both opening and closing, and go that inadvertent relative motion of the auxiliary switchblade with reference to the main switch arm is automatically prevented until the main switch arm is in its correct position for the closing motion of the-auxiliary switch blade to occur.

Further than this, the construction is such that means are provided ,for guiding the auxiliary switch blade into place and that floating stationary' contacts are provided which are spring urged inwardly and assure an intimate surface contact between themselves and the auxiliary switch blade.

Further than this the constructionprovides a hood closed at the'top and protecting the stationary contacts from the weather, sleet, ice and rain 85 for instance, and in which means are provided for overcoming any sticking or binding that may occur between the stationary contacts and the auxiliary switch blade without placing breaking strains upon the insulator stacks. The auxiliary switch blade is merely pulled downwardly, thus at most placing a compressive stress on the insulator stacks carrying the stationary contacts. There is no tendency to sway the insulator stacks or in any way harmfully stress them.

It is to be noted-that the stationary contacts project laterally beyond the insulators. For example, in Figure 1 the stationary contacts 43 extend beyond the insulator. Consequently there is no chance of snow piling up on the insulator and causing freezing around the contacts. In other words, the stationary contacts overhang the insulators so that any falling snow will clear the contacts and drop downwardly away from them.

Further it will be seen that a very simple, easily produced and reliable construction has been provided by this invention, it being understood, of course, that counterbalancing or the use of the counterbalancing spring as described in connection with the first form of the invention, may be used with any of the forms of the invention and if desired, the arc horns and the guiding springy arms carried by the main switch arm, as described in connection with the first form of the invention, can be used with any of the forms that the invention may take,

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather tact in one direction to switch-open position. an 76 auxiliary switch arm carried by said main switch arm, for engaging said contact andmovable in the reverse direction from' that of said main.

switch arm for switch-opening movement, a unitary operating means for first moving said auxiliary switch arm in one direction and thereafter moving said main switch arm in the reverse direction for opening said switch, said opcrating means first moving said main switch arm said main switch arm has moved from closed position. v

2. A switch comprising a hood having one side thereof open and having its opposite side closed,

a stationary contact located within said hood,

a main switch arm movable away from the closed side of said hood to switch-open position, an auxiliary switch arm carried by said main switch arm and movable away from the open side of said hood for switch-open position, a unitary,

operating means for first moving said auxiliary switch arm away from the open side of said hood and thereafter moving said main switch arm in the reverse direction from the closed side of said hood, said operating means when moved towards switch-closed position first moving said main switch arm towards the closed side of said hood and thereafter moving said auxiliary switch arm towards the open side of said hood and into engagement with said stationary contact, and looking means for temporarily locking said auxiliary switch arm to 'said main switch arm, said locking means being adapted to engage the closed side of said hood and releasing said auxiliary switch arm upon engagement with the closed side of said hood.

3. A switch comprising a hood having one side thereof open and having the opposite side closed, a stationary contact located within said hood, a main switch arm movable away from the closed side of said hood to switch open position, an auxiliary switch arm carried by said main switch arm and movable away from the open side of said hood for switch-open position, a unitary operating means for first moving said auxiliary switch arm away from the open side of said hood and thereafter moving said main switch arm in the reverse direction from the closed side oi said hood, said operating means when moved towards switch-closed position first moving said main switch arm towards the closed side of said hood and thereafter moving said auxiliaryswitch arm towards the open side of said hood and into engagement with said stationary contact, and automatic means for causing the sequential operation of said main and auxiliary switch arms when said operating means is moved, said automatic means including a latch for temporarily locking the auxiliary switch arm to the main switch arm, said latch being adapted to engage the closed side of said hood and being released upon engagement with the closed side of said hood.

4. In a switch, a switch blade, a hood having one side permanently open, a pair of contact members between which said switch blade is adapted to be received; means for holding said contact members in a floating manner to allow free adjustment thereof, spring means urging said contact members towards each other, and flexible leaders each having one end rigidly attached to one of the contact members, said leaders projecting from said contact members and eachhaving its other end'rigidly held in substantially the same plane as said first mentioned end for holding the contact members in approximate alignment with each other.

5. Ina switch, a switch blade, a hood having one side permanently open, a pair of contact members between which said switch blade is adapted to be received, means for holding said contact members in a floating manner to allow free ad justment thereof, spring means urging said contact members towards each other, said contact members being'in engagement with each other in a face to face manner when said switch blade is in switch-open position and engaging said switch blade in a face to face manner when said switch blade is in switch-closed position, and

flexible leaders each having one end rigidly attached to one of the contact members, said leaders projecting from said contact members and each having its other end rigidly. held in substantially. the same plane as said first mentioned end for holding the contact members in approximate alignment with each other.

6. A switch comprising a downwardly opening hood having a permanently closed top, a stationary contact mounted within said hood, a main switch arm pivoted at a point remote from said hood and movable upwardly to switch-open position, an auxiliary switch arm pivoted to said main switch arm and movable upwardly into said hood and into engagement with said stationary contact, means for moving said main and auxiliary switch arms, said hood having. laterally projecting stop means and said main switch arm having projecting means adapted to. rest upon said stop means when said main switch arm is in switch-closed position, are horn means carried by said hood and engaging said projectingineans during the final closing motion of said main switch arm, and means for directly guiding said auxiliary switch arm.

'7.'A switch comprising a stationary contact, a main switch arm movable away from said stationary contact in one direction to switch-open position, an auxiliary switch arm carried by said main switch arm for engaging said contact and movable to a position at an angle to that of said main switch arm for switch-opening movement, a unitaryoperating means for first moving said auxiliary switch arm to an angular position with reference to said main switch arm and thereafter moving said main switch arm to open position, said operating'mea'ns first moving said main switch arm towards switch-closed position and subsequently moving said auxiliary switch arm from its angular position to switch closed position into engagement with said stationary contact, automatic means for causing the sequential operation of said main and auxiliary switch arms, said automatic means including a latch for releasably locking said auxiliary switch arm to said main switch arm when said auxiliary switch arm is in its angular position and said main switch arm has moved from closed position.

WILLIAM O. SCHULTZ. ALWIN G. STEINMAYER. 

